Crankcase ventilator



y 22, 1-952 R. c. BECKETT 2,604,186

CRANKCASE VENTILATOR Filed Jan. '7, 1950 Roha/o/ C. Bee/(eff FREE. {7 aw zms Patented July 22, 1952 .onAN oAsE Ronald-oi Beckett, Galt,

A ro' has, calla Application'January v, 1950, Serial No. 137,349 I This invention relates to improvements in crank case ventilator devices for internal come bustion engines to be connected between the crank case and intake manifold. I

The principal object of the invention is to provide a crank case ventilator which'willafiord an improved metering action in the metering of the flow between the crankcase and manifold while eliminating clogging of the metering. orifice and in which there will be nofmoving partsin contact, to provide longer life and more dependable operation than previous ventilator devices. A further important objectis to provide efficiently for the settling out and filtering of contaminants drawnflfrom the crank case before metering the manifold directed new. b; If A further important object is to provide a crank case ventilator which will additionallyfunction as a vacuum breaker to prevent excessively high improved performance, i

manifold vacuums and consequentengine back:

firing. t a .A still further object is to provi-de'a simpleand compact device in which the parts can be readily removed, cleaned and replaced.

The principal feature of the invention consists in the novel arrangementIof a fixed tapered metering pin extended through a metering orifice in a flexible diaphragm in'ovingfrelative to and independent of the pin in response to variations in intake manifoldvacuum, tovary the annular flow opening around thepin inaccordance with desired flow at that vacuum. A further important feature consists in forming the tapered pinwith areverse taper to sharply increase flow passage under excessively high manifold vacuum to form a vacuum breaker to counteract the high vacuum and consequent en gine back-firing, or other improper operation.

which might-otherwiseresult.

A further important feature. consists-mar ranging aefilter element directly, in vthepath of flow moving towards the metering orifice to filter out contaminants in the flow drawnfrom the crankcase.

Another important feature resides in the pro vision of a sediment bowlbeneath the filter. element and arranging a bafflesurface either as part of or .separate from the filter element in the path of gas flow from'the crank case previous to the v 6Claims. (c1. 1ss--41) come apparent with reference to the accompanying drawings in which Figure 1 is a plan view of a crank case ventilator constructed in accordance'with my invention with part of the cover broken away. p

Figure 2 is a vertical mid-sectional view on the line 22 of Figure l.

'Figure 3, is a vertical sectional detail'of flow metering-device.

the

Figure 4 is a perspective view of the diaphragm employedin the flow metering. v Figure 5a representative graph of flow rate against vacuum obtained with a metering device constructed in accordance with my invention.

It is Welly-understood that, by connecting a valve betweenthe crank case and intake manifoldithe' crank case canbe ventilated to draw on contaminating materials in the bowl by gases or those formed as the result of oil deterioration.

The desirability of ventilation is well understoodfas the elimination of the contaminants prevent the inherent harmful effects such as rust; corrosion'and improper lubrication occasioned th'erebm Various formsof valves have-been provided. In nearly all of these there are moving parts in contact and the very nature of the contaminants being drawn therethrough'act to soon clog the valve and"freeze the moving parts. Consequently the valves operate efficiently to provide the desired flow metering action for relatively short periods when they must be serviced, cleaned or replaced. I i I It has also been attempted to eliminate contacting moving parts but insofar as I am aware no successful valving or metering action has been provided that will operate efficientlyover ex.- tended'periods.

Qne'of the prlmeobjects is therefore to over come the disadvantages of previous valve constructionsin the metering action, and further, to provide for filtering out the contaminants into a sediment bowl which can be readily removed With reference to the drawings, the device inclddes, as shown in Figure Z, a body portion l which may be in the form of a cylindrical casing filter element tosettle the heavier contaminants and deposit them in the sediment bowl. A still further feature of importance residesflin the novel fconstruction of parts. wherleinf the metering device, filter element and s'edimentjbowl form a compact simple structure.

having a transverse partition 2 extending thereacross, subdividing the interior of the casing and formed with a central boss 3 extending on opposite, sides of the partition and having a central screw-threaded bore in each face to'receive the metering pin 4 and the filter-retaining wing boltii.

Formed in the wall of the body portion I beengine. 'The partition 2 and cover 8 thus define a closedchamber H which is referred to as the metering chamber.

Clamped between the upper edge of the body portion l and the cover is a diaphragm l2 which 'subdivides the chamber ll extending thereacross between the inlet openings I3 in the partition 2 and the outlet ID in the cover. 7

Carried centrally on the diaphragm I2 is an orifice plate I4 clamped to the diaphragm with the aid of the annular clamping plate IS. The

orifice plate [4 is shown as provided with an upturned outer edge [-6 and an olfset inner edge H defining the metering orifice 18, the diaphragm being open beneath the metering orifice whereby communication between the partition inlet openings I 3 and the cover outlet i is afforded through the meteringorifice I8, I 7

Figure. 2 shows the normal position of the diaphragm under normal road load or driving condition with the biasing spring l9 counterbalancing the upward pull on the diaphragm by the vacuum in the intake manifold.

The spring I 9 is located by the boss-of the cover outlet t0 and the upturned outer'edge l s'of the orifice-plate.

As shown, the diaphragm provided as atZll with a corrugated formation to permit vertical movement of 'the orifice plate 14 relative the metering pin 4 over an extended vertical distance in accurate alignment with the pin.

Referring to Figuresz and 3, the metering pin x 4 tapers inwardly from 2| adjacent the top to the fiange base 22 and above 2| is reversely tapered at 23. The significance of the shape of this pin will be more fully understood with reference to Figure as hereinafter described.

-Thelower edge of the body portion I is shown asi-nter nally threaded at 24, and threading into the lower end is a. sediment bowl 25. Sealing the connection between the sediment bowl and the, body I is the gasket 26 compressed between the upper edge of the bowl and the shoulder 21 formed'within. the body portion of the device.

Surrounding the retaining bolt '5 and abutting the partition 2 is a removable filter element 28 7 held in place against the partition by the wing pressures obtainable with a metering arrangement in accordance with this invention. Under no vacuum in the intakemanifold, that is, the engine dead, the orifice plate M will be urged to seat against the base 22 of the metering pin by the biasing'spring l9, and it will be seen, with reference to both Figures 2 and 3, that as the vacuum increases to raise the diaphragm and plate M to the point 2|, the flow orifice defined between the tapered portion of the pin and the orifice plate will become progressively smaller, while above 2|, due to the reverse taper 23 of the pin, the area of flow through the orifice plate will sharply increase.

Under engine idling conditions the vacuum in the intake manifold is normally in the neighbourhood of 18 to 22 inches mercury and the bias of the spring I9 is such that at idling conditions the diaphragm is drawn up to bring the orifice plate I4 adjacent to the point 2| of the tapered metering" pin which is the largest diameter of the pin.

Thus the flow are'athrough the metering orifice I8 is at. a minimum." Any further increase'in vacuumin the manifold is prevented by the diaphragm moving'still'further upwardly to. the

dotted line position of Figure 3 to raise the orifice plate above the point 2l of the pin to increase nut '29. The Wall 30 of the filter element is spaced from the interior of the body portion I, defining an annular passage therearound, and

it will beseen from Figure 2 that gases delivered through theinlet. 6. which is adapted to be connected in communication. with a crank case to beventilated', willfimpinge on the wall 30 which wrill forma: bailie efiect to settle out the heavier contaminants in the flow and these will fall or drop down intov the sediment bowl.

The gases to'reachthe'open-ings l3 in the partition-must pass down beneath the filter element 28..and.such contaminants as are not settled out by. the bafile effect of the wall 30 will be filtered out by the filtering medium upon flowing upwardly to the metering. chamber ll, so that no contaminants will be permitted to accumulate aroundor on the metering pin 4.

Referring now to Figure 5, the curve 3| represents the typical flow rate for varying vacuum metering pin 4 and orifice plate [4, 'in'addition to serving in a metering capacity, serve as a vacuum break; V v

Thepurpose of. controlling the maximum mani- 'fold vacuum is to reduce engine oil consumption under high vacuum and toj'control engine backfire which occurs-if the manifold vacuum reaches in the neighbourhood of 25'inches mercury pressure.

With reference 'toFigure '5, it will be seen that the rate of'flow through the metering orifice I8 is substantially constant for manifold pressures in the neighbourhood of from 14 to 22- inches mercury. Above 22- inches mercury the curve breaks sharply at 32 to provide increased flow counteracting excessive manifold vacuum" leadin'g-to the 'oil' consumption, back-firing and other improper engine operation caused thereby.

Under normal road load conditions equivalent a manifold vacuum of from 8 to 12 inches mercury where crank case ventilation is important the flow rate through the metering orifice, due to the taper of the metering pin, increases to a maximum, as shown byth'e knee 33 of the curve, that is, the taper is'such in the pin 4 that, although the vacuum'ac'ting to draw the crank case gases through the inlet 6 in the ventilator device reduced, the area-of fiow through the metering 'o'rificeJI'B between themetering pin and the orifice plate is increased sufiiciently to provide the increased fiow'required.

of Figure 5 is by way of illustration only and the orifice plate It and meteringipin v4 can be modified to provide the precise flow rate required for any particular engine design.

It is; extremely importantto note that in the metering action there are no moving' parts in contact, the metering pin 4 is stationary and the orifice'plate l4 carried by the diaphragm is not in contact with the pin. At the same time there is a wiping action between the pin and orifice plate to prevent any build-up or accumulation of contaminants which may happen to pass through thffifilterfrom bridging andsealingthe metering Ce 7 ,9 .v

It will be understoo'dtthat' the specific curve It is also important to note that the diaphragm is independent of the metering pin and carries a minimum of load, in the form of the orifice plate 14 and clamping plate l5, which would deleteriously affect the alignment of the diaphragm in moving relative the metering pin.

Further, both the clamping plate and orifice plate lying against the diaphragm and substantially in the plane of the diaphragm serve in clamping the diaphragm to prevent any turning or twisting movement therein in operation which would serve to alter the accuracy of the metering.

The provision in a single unit of a filtering medium and a sediment collector and a metering device is also important as the metering action is improved by the elimination of the contaminants and no special provisions, fittings or the like need be applied in using the ventilatordevice. Further, the bafile arrangement and large filter area provide for long periods of operation without attention by eliminating the necessity of the filter to handle all of the contaminants and by preventing any consequential accumulation of contaminants in the metering chamber.

Further, the simplicity, ease of removal of parts for cleaning, replacement or the like is apparent.

It will be understood that various modifications in the construction and assembly of the parts may be made without departing from the spirit and scope of this invention.

It is important to note that by providing for the filtering and collecting out of impurities and oil bodies and the like from the flow, not only is the metering action improved and build up of accumulations around the metering elements prevented, but further such foreign matter and accumulations is prevented from entering the engine manifold and consequent harmful effects which would be occasioned by such entry are prevented.

What I claim as my invention is:

1. In a crank case ventilator, a metering chamber having an inlet thereto for communication with a crank case and an outlet therefrom for communication with an intake manifold, a diaphragm extending across said chamber between said inlet and outlet and having a metering orifice opening therethrough, a tapered metering pin supported within said chamber and concentric with said metering orifice to project therethrough and tapering toward the inlet side of said diaphragm, and means biasing said diaphragm towards said inlet.

2. In a crank case ventilator device, a metering chamber having a crank case connecting inlet thereto and an intake manifold connecting outlet therefrom, a diaphragm extending across said chamber between said inlet and outlet, an orifice plate carried by said diaphragm and pre senting a central metering orifice opening therethrough afiording communication between said inlet and outlet, a metering pin supported within said chamber andconcentric with said metering orifice and normally projecting therethrough with the portion normally projecting through said orifice tapering towards the inlet side of said diaphragm, and spring means biasing said diaphragm toward said inlet, the diameter of said I orifice being greater than the maximum diameter of the tapered portion of said metering pin.

3. A device as claimed in claim 2 in which said pin is also tapered on the outlet side of said diaphragm.

4. A crank case ventilator device, comprising a body casing having a transverse partition subdividing said casing into an upper metering chamber and a lower filtering chamber and formed with a central boss and having an opening therein providing communication between said chambers, a metering pin threaded into said centre boss and tapering toward said boss, a cover member closing said upper metering chamber, a diaphragm clamped by said covering member and extending across said metering chamber and formed with a metering orifice receiving said metering pin, spring means biasing said diaphragm, a filter element arranged beneath said partition in said filtering chamber, retaining means threaded into said central boss removably retaining said filter element in said filtering chamber, a sediment bowl closing said filtering chamber, said filtering chamber having an inlet Y therein leading to said sediment bowl and said REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,990,657 Krieck Feb. 12, 1935 2,450,864 C'allaway et a1. Oct. 5, 1948 

